Structured Odorant Response Patterns across a Complete Olfactory Receptor Neuron Population

Abstract

Odor perception allows animals to distinguish odors,recognize the same odor across concentrations, anddetermine concentration changes. How the activity patterns of primary olfactory receptor neurons (ORNs), at the individual and population levels, facilitate distinguishing these functions remains poorly understood. Here, we interrogate the complete ORN population of the Drosophila larva across a broadly sampled panel of odorants at varying concentrations. We find that the activity of each ORN scales with the concentration of any odorant via afixed dose-response function with a variable sensitivity. Sensitivities across odorants and ORNs follow a power-law distribution. Much of receptor sensitivity to odorants is accounted for by a single geometrical property of molecular structure. Similarity in the shape of temporal response filters acrossodorants and ORNs extend these relationships tofluctuating environments. These results uncover shared individual- and population-level patterns that together lend structure to support odor perceptions.